the region is bounded by the x-axis and the graph y = f(x) and the
solid is obtained by rotating the region about the x-axis, then we
need to find the integral π∫ab
dx, where either the interval a ≤ x ≤ b is given or its endpoints
are found as x-intercepts of the graph y = f(x).
case when the region is bounded by the vertical lines x = a, x = b,
and the graphs y = f1(x)
for a ≤ x ≤ b, the volume of the solid obtained by revolution of
the region about the x-axis equals π∫ab
PS. If you have specific questions about this volume, please let me know.